High iso IQ is indeed very much a requirement for action photography. Almost all my action shootings are done at iso 400, many at iso 1600 to 3200, here is are a few just to give you the idea.

It has not stopped me taking photos of high speed action...

It probably did, because in practice what happens with FZ150 is once ISO hits 1600 ( maybe even 800), it simply is not worthwhile taking them because the IQ would be too low for a keeper. If you dont agree then why dont you show us 5 iso 1600 keepers you got from FZ150?

You're still talking about IQ.

And I have never claimed that my superzoom can match a DSLR's IQ (quite the contrary).

I am not talking about IQ in the sense that SLR's IQ is better so one should buy SLR for general use. I am talking about IQ in the sense that it is one of the necessary requirements for action photography.

You obviously recognise the necessity of good AF, good shutter lag for action phtography, because without them your keeper will be very few. high iso IQ is no different to good AF in that sense - if a camera cannot deliver good high iso images, it will severely limit where and when can you do action photography.

My FZ cameras do not prevent me shooting action. Previous superzooms I owned (eg. Fuji HS10), DID literally stop me shooting action, because they just didn't have enough performance in the areas I mentioned (plus HS10 blacked out EVF/screen when saving to card :-P).

Like i said, your FZ does indeed prevent you from shooting action because there ought to be times where its iso 3200 simply is not good enough to keep. All cameras have this limitation. for 60D, its IQ becomes not worth keeping at over 6400, for 1DX, the bar is even higher but it still exists.

My image quality doubtless wouldn't meet your standards, but if it prints OK at 6x4 it's good enough for me. As I keep saying - I'm not a pro, and I don't need pro-standard IQ.

I am not a pro either , few action shooters are. most people just do it as a hobby. But we still prefer better IQ.